Electrical connector



Oct. 29, 1957 w. SCHUMACHER 2,811,705

ELECTRICAL CONNECTOR Filed Sept. 25, 1955 INVENTOR, 14 4 z/AM Z \S'C'HUMA 6/1 51? United States Patent ELECTRICAL CONNECTOR William L. Schumacher, Harrisburg, Pa., assignor to AMP Incorporated, a corporation of New Jersey Application September 25, 1953, Serial No. 382,405 4 Claims. (Cl. 339-276) This invention relates to electrical connectors of the flag type and particularly to connectors or wire terminals of the flag type in which a ferrule forming ear integral with the root portion of the connector is struck up from within the flag portion of the connector and bent back upon the root portion, the flag portion being also provided with a binding post opening.

More particularly the invention aims to provide a terminal of the flag type having a ferrule-forming ear struck up from the root portion which is so sharpened at its end, as by swaging, that when crimped it will either pierce the insulation of the wire for which it is to form a connector and come into contact with the conductor part of the wire or when used with the stripped end of a stranded conductor will wedge between and tightly engage the strands as it is crimped into confining relation thereto.

An important feature of the invention is the provision of a lead or pilot opening in the blank from which the connector is to be formed, which lead opening is of such shape that it defines and determines the blank location of the end of the ferrule-forming car which is to be struck up from the root. or body portion of the connector. Since the most effective stranded conductor engaging end on a ferrule-forming ear is one which is at right angles to the car itself and which has an engagement with the conductor substantially parallel thereto, the lead or pilot opening initially provided may conveniently be of substantially triangular shape, whereby one of the sides of the triangle may define the conductor wedging end of the ferrule-forming ear.

Another important feature of the invention is the formation of the connector-forming blank in its early stages so that a compact flag connector having two opposed conductor engaging ears may conveniently have both ears swaged to a strand wedging sharpness while the blank is under accurate and positive control.

Another important feature of the invention is the arrangement of the lead or pilot opening aforementioned so that, after the swaging operations have been performed upon the ferrule-forming ears, the lead or pilot opening may be substantially eliminated by the formation of the binding post receiving opening in the flag portion of the connector.

Other objects and important features of the invention, to which reference has not specifically been made hereinabove, will appear hereinafter when the following description and claims are considered in connection with the accompanying drawings, in which- Figure 1 is a plan view showing a strip of suitable sheet metal of a width substantially equal to the overall length of the connector blank, this view showing the successive steps of forming the connector of the present invention, preferably in the form of a strip of separable connectors;

Figure 2 is a perspective view of an uncrimped flag connector embodying the present invention and made by the method herein set forth;

Figure 3 shows a connector of the present invention crimped into connective relation to the stripped end of an insulated conductor;

Figure 4 is a side elevation illustrating the method of crimping the flag connector into conductive relation to a stripped conductor end;

Figure 5 is a section through the crimped conductor on the line 55 of Figure 4;

Figure 6 is a plan detail showing the relationship of the original pilot opening to binding post receiving holes of various sizes;

Figure 7 shows a strip in which flag conductors of the present invention are separably joined together by connections between their ferrule portions as distinguished from the flag connectors shown in Figure 1;

Figure 8 is a plan view of a blank from which a flag conductor can be formed, having, in addition to the conductor-engaging ears, an ear that can be wrapped around the insulation;

Figure 9 is a plan view showing the conductor of Figure 8 crimped upon the stripped end of an insulated conductor.

Referring to the drawings, a strip of suitable sheet metal 2, such as copper or a suitable alloy thereof, is first provided with a lead opening 4 of substantially triangular shape, the triangle preferably having rounded corners. The side 6 of the triangular opening 4 defines the end of an ear 8 to be turned up which will form a part of the ferrule of the connector.

The lead or pilot opening 4, which is formed at station a is used for piloting at station b. At station 0 the swaging of the ends of the ferrule-forming ears to be later cut from the blank begins. It will be seen that the swaging of the end of the ear 8 can begin at station c by reason of the formation of the triangular pilot opening 4. Since the blank 2 is of a width equal to the over-all length of an individual connector blank, it will further be seen that the swaging of the end of the ear 10, later to be formed, can also begin at station 0, the end of this ear coinciding with the edge of the strip 2. The swaged end of the ear 8 is indicated at 12 and the swaged end of the ear 10 is indicated at 14. For convenience in locating the strip 2 for the next operation, a second pilot hole 16 is punched in the strip 2 between stations 0 and d, this pilot hole serving to locate the strip for the connector profiling at station e. This second pilot hole, which is a round hole, is punched in a part of the strip which will be removed in the profiling of the neck portion of the connector. As shown in Figure l, the connector profiling step, as just suggested, begins at station e, that is, the profiling means operates upon a part of the strip located at station e and a part of the strip located at station g. The triangular lead hole 4 is again used to pilot the strip for the punching of the post hole opening 18, the post hole preferably having lateral notches 20 to receive ribs or pins on the binding post to keep the connector from turning, as shown at station h. At station 1' the ear 8, which is to be struck up from the body of the connector blank, is sheared therefrom and at station k the punch press operations are completed with the striking up of the two ears 8 and 10 into U form preparatory to their receiving the conductor to be connected thereto.

As shown in Figure l, the connectors are preferably made in continuous strip form with joining strips 22 between successive connectors which are severed when the connectors are attached to conductors.

It will be seen that connectors embodying the present invention can be provided with binding post openings of various sizes, for example, a binding post opening 24 of an area that would include some of the space formerly occupied by the ferrule ear 8 may be provided if desired.

In the form of the invention shown in Figure 7,, the connectors are shown made in a strip in which the ferrule parts of the successive connectors are connected, as shown at, 26. The procedure in making this form of connector strip, however, is substantially the same as that employed in making the strip shown in Figure I.

In Figure 8 is shown a modification of the connector. In the form shown in Figure 8 there is left on one side of the connector, and immediately, adjacent to the ferruleforming ear 10, a strip 28, as shown in Figure 9, which may be wrapped, around the insulation further to insure the maintenance of the connector in its attached relation to an insulated conductor. This wrap-around strip also maintains the insulation against frayingadjacent to the connector.

What is claimed as new is:

1. The method of forming from a strip of sheet metal a flag terminal having a sharp-ended ferrule-forming ear struck up from within the body portion thereof including the steps oi first punching, a substantially triangular lead hole for piloting the strip through a multistage die-forming operation, one side of the lead, hole defining the end edge of the ear, swaging the end edge while the ear is substantially coplanar with the strip to the desired sharpness, blanking the outlines of the terminal leaving a connecting severable neck between successive blanks in the strip, moving the strip to a post hole punching stage by pilotingqon the lead hole, punching a binding, post receiving opening overlapping the lead hole so as to eliminate substantially the sides of the lead hole other than the one side, and stamping up the ferrule-forming ear from the body portion of the terminal.

2. A process as defined in claim 1 in which a strip of sheet metal of a width substantially equal to the overall length of the terminal in its flat condition is employed and an opposed insulation-piercing, ferruleforming ear to be stamped up from the terminal base has its end edge coinciding with one side of said strip,

whereby it may be swaged into the desired sharpness simultaneously with the swaging of the first-mentioned ear.

3. The method of forming a strip of sheet metal flag terminals each having a pair of opposed sharp-ended ferrule-forming ears including forming a strip of sheet metal of a width substantially equal to lateral pre-blanked dimension of the terminals; and forming each of the terminals by punching in the strip a pilot opening having at least one substantially straight edge, one side of the strip and the straight edge of the pilot opening defining the end edges respectively of the pair of ears; swaging the ends of the pair of ears to sharpen the edges thereof; blanking out for each terminal a ferrule portion having a root portion intermediate and approximately equidistant from the swaged ear ends and a flag portion extending laterally from the root portion including the pilot opening; enlarging the pilot opening to form a binding post receiving opening; and stamping up the pair of ears and bending the same back upon the rootportion.

4. A flag-type sheet metal electrical connector comprising a flag contact portion and an integral root portion from one side of which said flag portion projects, said root portion providing the base of a ferrule extending at right angles to the length of said flag portion, interior edges in said flag portion defining a cruiciform opening including, a post portion and an arm portion, the upper end of said post portion being arcuate for cooperatively receiving a binding post, and an upstanding ferruleforming ear integrally extending from said one side of the root portion, said upstanding ear extending from the lower edge of said post portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,436,852 Carmichael et al Mar. 2, 1948 2,476,429- Paules July 19, 1949 2,648,050 Berg Aug. 4, 1953 2,680,235 Pierce June 1, 1954 FOREIGN PATENTS 884,641 France Aug. 23, 1943 

